datatable headerStyle is applied to body and footer colgroups. headerClass is not.

[WhyKickAmooCow]

I have run into this trying to use headerClass for horizontal scrolling.

When using headerStyle, the style is applied to the header and colgroups in the body and footer (this means the whole column is the same width for example). This isn't the case when using headerClass. The expected behavior was to apply the class to the header and colgroups like headerStyle, but instead it is only applied to the table header. This results in the header being larger than the body and stops the horizontal scrolling from working as expected (since I am using a headerClass to set width).

[WhyKickAmooCow]

This is likely a duplicate of the issue faced in #861, but not what is described in #861.